Crystal structure of N-(p-bromophenylcarbamoyl)thiamine anhydride (N,S-trans-type)

Abstract

The crystal structure of N-(p-bromophenylcarbamoyl)thiamine anhydride, C₁₉H₂₀BrO₂N₅S, has been determined by three-dimensional X-ray analysis. The crystals are monoclinic, a= 12·460, b= 13·510, c= 12·006 Å, β= 93°27′, Z= 4, space group P2₁/c. The intensities were measured with a Hilger and Watts automatic four-circle diffractometer using Mo-K_α radiation. The structure was solved by the programme SEARCHER, for the automatic heavy-atom analysis, and refined by full-matrix least-squares calculations to a final R of 0·054 for 2396 independent observed reflexions. The locations of 20 hydrogen atoms have been determined from a difference-Fourier synthesis. The molecule has two intramolecular hydrogen bonds.